'06 Suddenly Burning Oil... Lots...

Have you ever monitored the oil consumption over a complete oil change interval prior to this happening? If so what was the pre-existing consumption like?

BTW. Do you know exactly what type and quantity of oil was used at 140 kmile, and who performed the service?

 

The oil light only comes on when there is no oil pressure, at which point substantial damage can already be done. You might be lucky, in that you seem to have caught it fairly early, but unfortunately the only "sensor" that will reliably warn you in time to prevent engine damage is the dipstick.

 

How much oil is in the crankcase when you have just a little bit reading on the end of the dipstick? On my POV it means that there are 4.5q remaining out of six. I'm not sure about Priuses, but if there really is oil present on the end of the dipstick, then that means that there is oil in the crankcase.
The engine might not be burning as much oil as you may think.

Leaving aside all of the opinions and guestimations about sticks and levels you need to answer a few basic questions.
1. How much oil is the car using in 5K?
2. What is your current MPG versus the lifetime over the last 60K miles?
3. What are your intentions for transportation over the next 3-5 years?
4. How important are emissions to you?

I've seen people run cars that are burning oil @ 1q/1000 for YEARS, and I've seen people run screaming to their local car dealers to replace a car that's burning a half quart over five thousand miles.

The above are questions that YOU have to answer for YOU.
As far as I'm concerned if a car gets good mileage and the county isn't wanting to hire you for mosquito control, then you'll just need to assiduously monitor your oil consumption and wait for something else to break.
Remember....in a Prius you're traveling most of 500 miles between tank fill-ups---or at least I do.

If you check your oil every other tank that's every thousand miles. I can get away with that since I'm the one that changed the oil in my cars, and I know that the right oil was used and that the filter was changed...etc.
Moving forward...if you have somebody else do your oil changes then you might want to check your oil level more often.
Since you don't live in an oppressive state that forces you to endure VET (Vehicle Emissions Testing) then if you wish, you can get a CAT on eBay for 500 bucks and tell your local dealer to rob somebody else, or you can fix the little "change owner" light with a small piece of electrical tape.
Unfortunately, that will also mean that the little light will not warn you about the next engine problem.
That's your call too.


Good Luck!
Merry Christmas!

 

That is so true uart. It sounds like the OP may not have been monitoring oil use.

Tell us more jrgordon. Have you had somebody change your oil for you? Do you know if it was low at every oil change?

Usually what happens if someone else changes your oil for you, they overfill it (which causes leakby problems in the combustion chamber and will cause your car to "burn" oil). Then your car starts burning oil, once this starts its kind of a runaway thing (it keeps getting worse). If you don't check your oil regularly, you won't know this is happening. Then when it gets so bad, the warning light comes on or worse, your engine goes. If your car is burning 2+ quarts in less than 5k miles, your engine likely needs replaced.

 

Lots of oil loss Prius threads. Most have these few things in common:

Owner does not change oil themselves and or do not check the oil level at every fill up. Oil is never checked prior to change out to see if any progressive minor oil loss.

Owner takes his car to the dealer to have the oil changed. They use there "regular" oil which is vat dino unless customer requests synthetic which is expensive at there place. Dealer never checks oil before dumping it and reports to owner hey your oil was low you need to watch it. They just pull the plug and then usually overfill it. Oil loss begins because of lifetime of poor quality oil and or running it consistently low OR extremely overfilled which if dealer serviced I can almost guarantee its not filled accurately especially if using there VAT oil and not bottle fed. There VAT oil is dispensed by air gun out of the vat and quantity dispensed is notoriously inaccurate so they error on the overfilled side. Couple that with the fact they really don't care as oil changes are just a nuisance to them and it really doesn't turn out all the well.

Minor oil loss is never noticed between changes as no one checks the oil. But minor oil loss contributes to poor lubrication systematically and continues to exacerbate the issue. 50-70-90K miles later oil loss is now severe and for the first time the car runs so low on oil it throws a check engine light which alerts the owner to a problem. About 90% of Prius owners on this site as far as I can tell when seeing this cel never even open the hood to check oil or fluids. Car is taken to dealer, mechanic, jiffy and the oil now so low its throwing oil pressure light. Then it's omg how did this happen?

At least at a mechanic or jiffy they check the oil before sending the car. This is not done at the dealer based on the amount of complaints seen here over the last 7 years.

After a Prius goes through this "cel light on from no oil pressure" incident it then begins to really eat oil. This event really damages the oil ring and scuffs the cylinders.

To further complicate the matter alot of people on this site over the years recommend to not run your oil to the full line to improve mpg's. That's ridiculous especially if not closely monitored. This little motor needs every drop of oil it was designed for.

This car has VVT variable valve timing and that is accomplished by an oil control valve, a oil driven actuator on the cam, and its own little filter. It requires the proper amount of oil and oil pressure to work properly. I would imagine engine performance suffers greatly driving around on low oil.

Btw, drop of oil at bottom of dipstick means its about 2.5 quarts low maybe more. The engine holds 3.5 quarts. Pretty much empty.

 

I can't afford to buy a new car every 3-5 years.
Well.....actually I can afford it, but only because I don't.

THAT's why I can't afford a "free" dealer maintenance plan...or letting Jiffy Lube do it, although the Jiffy place at least will put bottle oil into the car if you BYOB, and you can WATCH them actually change the filter.
Modern cars are pretty durable. Even with marginal maintenance they're pretty much guaranteed to last > 100,000 miles.
Did you ever wonder why many people who are over 50 suddenly start paying attention to cholesterol, exercise, and become much more health conscience in general???

 

Assuming you went through 2.5 quarts in 5K miles, that's a quart every 2K. Not at all what I'd call significant oil consumption, particularly for a car with 145K miles. My Mazda3 uses one every 3K or so at 135K miles. Heck, if you had this level of oil usage within the factory warranty period, Toyota wouldn't do anything about it. According to this Toyota dealer site:

According to our mechanic contact, Toyota’s “normal specification” for oil consumption is 1 quart every 1,200 miles.​

I'd check it at every fill up until you have an idea of how bad it's using oil, then you can check it less often. If it gets real bad (a quart every 500 miles or less), then you can think about a used engine or a repair. Otherwise, oil's cheap.

 

Yes it really doesn't matter how much oil you use or lose what matters is not to let it run empty.
That requires frequent checks as you know.
Even at your oil loss as long as you keep it up and not let it run dry the engine will probably run fine for quite a while.

What I would do is try running some very high performance lubrication and go up one more weight to 40 and see if you can improve that.

I'm running this stuff and its really really good oil. In fact they tout less oil loss too. Also it claims thicker operating film too so its like a 40 weight. My 07 at 60,000 miles was losing about a 1/8 of an inch on the stick every 5000 miles on M1. On this stuff I'm at 3,000 miles and it hasn't moved off the full line on the stick:


Red Line Synthetic Oil - Motor Oil - 5W30 Motor Oil

 

jrgordon, the question above is what I would like answered also. To put it bluntly, do you "regularly" check your oil level on your dipstick? By regularly I mean "every time you buy gas".

If the answer is yes, then the next question would be the same as above. What was the consumption like?

 

The engines we have seen disassembled here show carbon buildup and sticky oil rings to be the some of the causes of oil consumption on the Prius ICE. I am unsure of the results others have had with Marvel Mystery oil and the like in freeing up the rings.
As to the amount of the consumption, if it's only about a quart every 2k miles, that's within the acceptable range.

Could the oil consumption cause the P0420? If it's bad enough, burning oil can foul the converter. My advise would be to monitor the oil consumption to get a handle on exactly how bad it is before proceeding further with any repairs.

 

A few things to share on my experience with my Prius using oil.

1. Switching to a synthetic oil: My Prius never used oil until I switched to a synthetic blend. If you have an older car that has used regular motor oil for years then, in my opinion ,you should never switch to a synthetic. I made this mistake and my Prius started using oil immediately.

2. Will a Prius that is eating oil cause the check engine light to come on with a P0420? Yes, this happened to me when my Prius started using oil. It can ruin the catalytic converter by it trying to vaporize all that oil.

How I am trying to attempt to correct the oil consumption:

1. I am using a Lucas oil Treatment with regular 15W-30 motor oil to hopefully try to lubricate the rings and stop the oil consumption

2. I am also using techroline additive in my fuel for a few fillups to clean out the fuel side of the engine.

Results:

So far my oil consumption has disappeared, but I still want to put a few more miles on the car to determine if the oil consumption has definitely stopped.

The check engine light has also gone out(Throwing code P0420) after I used the oil treatment and Techroline.

I will update further in a few weeks to let everyone know if the oil consumption has stopped.

 

westy,

Surely you mean loosen the rings, not lubricate them. The engine oil already lubricates them. the Lucas oil treatment is used to loosen them (it's claimed to do so any way).

All the Toyota four cylinder engines I've owned (Camry 2.2L, Corolla 1.8L, and Prius 1.5L) have used oil (internally primarily) after 150+K miles. The two Honda Civic 1.5L engines I've owned, on the other hand, had low oil consumption even with 200+K miles.

IMHO, adding a quart every 2000 miles is not a big concern on a Toyota with 150+K miles. However, neglecting to check the oil level between changes and adding oil as needed shows the owner is lazy, ignorant, or both. If such neglect happens to increase the oil consumption, well, that's the fault of the owner, not the vehicle.

 

When you say using oil "lots" there isn't much to lose...when I fill my 06 it is 3-qts + maybe 1/2 qt more...

 

Hmmm. It sounds to me like you are not one to check the oil level on the dipstick when you refill the fuel tank.

All engines tend to use oil over time, some more so than others. It is unfortunate that your Prius is using a "excessive" amount at this time. You can try thicker oil, oil treatments and what have you but in the end there really is no magic fix that you can pour in from a bottle.

One thing that really exacerbates oil usage in my opinion is lack of oil and lack of maintenance. I would suggest that in the future you take the time to check your oil level in your ICE, no matter what brand, make or model thereof. You might find that it will make no difference, but on the other hand you might find that it makes a world of difference.

FWIW, there are many threads here on PC like yours. Most of them revolve around those who simply don't check their oil between changes. From what you said, it sounds like yours is very similar. The rest of the threads are generally Pri with higher mileage and oil usage is cause by normal wear and tear which as I stated are common with just about all ICE at one time or another in its life. Normally, oil usage starts out slow and continues gradually getting worse over time. All at once radical changes usually is a sign of neglect or failure of a component due to "lack of lubrication".

If you think I am trying to put you down, I am not. So please don't take it that way. You yourself admit you were lax in that department (not worrying about oil loss).

The Prius engine does not hold a lot of oil. Once the ICE gets low on oil, damage occurs. After that oil usage is one of the first symptoms and it just gets worse as time goes along. Maximum fill is 3.9 quarts with a filter change. When the red triangle lights up due to low oil pressure, you are generally down almost two quarts. That is almost half of what should be in there which is surely not enough. Bottom line, check your oil at every fill up. Keep it topped off and you should have better luck.

 

Unless your real world name is "owner", then it should have been obvious to you that my post was not directed at you.

 

Yes Louisa Ky is not the best place to break down as far as finding a repair shop but there are a lot of real nice people that go out of there way to help a stranded motorist!! Glad you made your flight lol.

 

Yes loosen the rings would be correct. Can you tell I am not a mechanic lol. I did check my oil frequently and I had no Oil usage until I was talked into switching to synthetic oil at a quick lube. In my research on switching to synthetic in an older car that used regular motor oil for years, I have found many people who claim to have had a similar experience as I did.